Refinement of pre-exposure programs to reduce the use of fish in proliferative kidney disease monitoring in aquaculture

The aim of this proposal is to optimise the Proliferative Kidney Disease (PKD) experimental challenge model to limit the use of fish as sentinels of disease in research. We propose to achieve this by adapting methods developed previously by us 1) to quantify parasite dose by water sampling and detection of environmental DNA and 2) to measure PKD specific immunity in exposed fish using serology. These methods will provide a novel best-practise challenge protocol, and a challenge monitoring toolkit. The main 3Rs advance will be to reduce the number of fish required to reach statistically acceptable sample sizes, allowing future scaling up of large field trials during vaccine development work.